• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

Cisco 2950 gigabit uplink only does 10 or 100 mbit

V

Viper GTS

Lifer
I was given a 2950 that had no OS on it. I've downloaded & installed the latest IOS available for it & I have basically everything working.

The only thing remaining is one of the two gigabit uplink ports will only do 100 mbit. The other will auto-negotiate to 1000 with no troubles using the same cables/connections but gi0/1 will only negotiate to 100 at best & it's currently sitting at 10. Setting it manually to 1000/full causes the link to go down and never return.

What should I be looking at for a solution? Is this likely something that can be easily/cheaply fixed?

Viper GTS
 
Is the cable connected to the gig ports commercial or hand made?

If hand made, try a commercial cable. If it's a commercial cable, try another.

All four pair have to be up-t-spec, or it'll never negotiate the gig link.

Also, Old Cisco gig ports DO NOT negotiate auto-mdi ...if you're going to another switch (or similar), you need a gig cross-over cable (all four pair cross 1&2->3&6, 4&5->7&8)

Good Luck
 
All the cables are commercial, & I've tried multiple. The other port has no issues using the same cables, including into my existing unmanaged gig switch. None of the cables are crossover, but I am getting a connection through the 2950 using them so it's being negotiated correctly.

At this point I'm relatively sure it's the 2950's problem, but I don't know enough to differentiate between a hardware problem and a config problem (though I'm leaning towards hardware since my config was fresh + the other port works as I would expect).

Viper GTS
 
User Access Verification

Password:
Cisco2950>en
Password:
Cisco2950#show run int gi0/1
Building configuration...

Current configuration : 36 bytes
!
interface GigabitEthernet0/1
end

Cisco2950#show run int gi0/2
Building configuration...

Current configuration : 36 bytes
!
interface GigabitEthernet0/2
end

Cisco2950#

That what you were looking for?

Viper GTS
 
The switch will do post tests when it boots. Have a console cable on it and watch the port tests. I think the command for 2950 is show post or show test. Don't deal with them much.

Other than that the biggest cause is still at the physical layer. What's the other end of the link and what is it's configuration? You can't do process of elimination to troubleshoot networking so just because it works on something doesn't mean it's good.

No link means layer1 is broken.
 
I've tried my existing switch (which will successfully negotiate at 1 gb on port g0/2) and an Intel Pro/1000 adapter set for auto and 1000 full. When set for auto the Intel adapter does 10 or 100 in g0/1 and 1000 in g0/2. Setting it to 1000 full drops the link in g0/1.

Show post just returns passed (from telnet), I'll have to either move the switch or setup a long cable for a console capture. I don't see any errors in the port status though when it's running at 10 or 100.

Viper GTS
 
spidey07 said:
The switch will do post tests when it boots. Have a console cable on it and watch the port tests. I think the command for 2950 is show post or show test. Don't deal with them much.

Other than that the biggest cause is still at the physical layer. What's the other end of the link and what is it's configuration? You can't do process of elimination to troubleshoot networking so just because it works on something doesn't mean it's good.

No link means layer1 is broken.
Click to expand...

Pretty sure its show post on these, at least it is on 2960
 
i thought gigabit was AUTO in standard. only 10/100 was fixed at full.

you sure you got the latest ios on there? not an ancient version?
 
Emulex said:
i thought gigabit was AUTO in standard. only 10/100 was fixed at full.

you sure you got the latest ios on there? not an ancient version?
Click to expand...

It defaults to auto, but I tried setting it to see if it might be a negotiation problem.

Here's what I'm running:

Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(22)EA13, RELEASE SOFTWARE (fc2)

Unless I totally missed something on their website I believe that is the latest available for the 2950.

Viper GTS
 
Just an idea...I would check the actual port for physical damage. I had a person plug try to plug in an rj11 into a port one time. They bent the first and last pins on the port. the port would still do 10-100, but no gig, since gig uses all the pairs.

John
 
yeh i've seen bad ports - especially on ebay junk. then again if they used it for fiber they'd never really notice.

got any gbics?
 
As a side note, I have several 2950's in my lab environment. I would probably be willing to trade if you could pay for shipping!
 
MPLR_2950_1#show ver
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(20)EA1a, RELEASE SOFTWARE (fc1)
....
Model number: WS-C2950T-24

MPLR_2950_1#show int g0/1
GigabitEthernet0/1 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 0012.7fd8.83d9 (bia 0012.7fd8.83d9)
MTU 1500 bytes, BW 1000000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:04, output 00:00:04, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 2000 bits/sec, 3 packets/sec
5 minute output rate 38000 bits/sec, 6 packets/sec
15612 packets input, 1821791 bytes, 0 no buffer
Received 14661 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 13761 multicast, 0 pause input
0 input packets with dribble condition detected
234228 packets output, 236482553 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out

Running to an intel pro/1000 GT desktop adapter (Microsoft 8.4.1.0 driver, Windows 7) in PCI over a crappy 100' cable coupled with a 50' cable (just to push it). Still came up great.

MPLR_2950_1# show run

interface GigabitEthernet0/1
switchport mode trunk
speed 1000
duplex full
!

(config hardcoded for switch to switch w/ etherchannel).
 
Last edited:
You must log in or register to reply here.

TRENDING THREADS

Back
Top